Configuring a registry

The Registry configuration is based on a YAML file, detailed below. While it comes with sane default values out of the box, you should review it exhaustively before moving your systems to production.

In a typical setup where you run your registry as a container, you can specify a configuration variable from the environment by passing -e arguments to your docker run stanza or from within a Dockerfile using the ENV instruction.

To override a configuration option, create an environment variable named REGISTRY_variable where variable is the name of the configuration option and the _ (underscore) represents indention levels. For example, you can configure the rootdirectory of the filesystem storage backend:

storage:
  filesystem:
    rootdirectory: /var/lib/registry

To override this value, set an environment variable like this:

REGISTRY_STORAGE_FILESYSTEM_ROOTDIRECTORY=/somewhere

This variable overrides the /var/lib/registry value to the /somewhere directory.

In order to override elements of a list, provide the index of the element you wish to change as part of the path to that element. For example, to configure the hosts list under letsencrypt:

http:
  tls:
    letsencrypt:
      hosts: [myregistryaddress.org]

The corresponding environment variable would be:

REGISTRY_HTTP_TLS_LETSENCRYPT_HOSTS_0=registry.example.com

Note: Create a base configuration file with environment variables that can be configured to tweak individual values. Overriding configuration sections with environment variables is not recommended.

If the default configuration is not a sound basis for your usage, or if you are having issues overriding keys from the environment, you can specify an alternate YAML configuration file by mounting it as a volume in the container.

Typically, create a new configuration file from scratch,named config.yml, then specify it in the docker run command:

$ docker run -d -p 5000:5000 --restart=always --name registry \
             -v `pwd`/config.yml:/etc/distribution/config.yml \
             registry:2

Use this example YAML file as a starting point.

These are all configuration options for the registry. Some options in the list are mutually exclusive. Read the detailed reference information about each option before finalizing your configuration.

version: 0.1
log:
  accesslog:
    disabled: true
  level: debug
  formatter: text
  fields:
    service: registry
    environment: staging
  hooks:
    - type: mail
      disabled: true
      levels:
        - panic
      options:
        smtp:
          addr: mail.example.com:25
          username: mailuser
          password: password
          insecure: true
        from: sender@example.com
        to:
          - errors@example.com
loglevel: debug # deprecated: use "log"
storage:
  filesystem:
    rootdirectory: /var/lib/registry
    maxthreads: 100
  azure:
    accountname: accountname
    accountkey: base64encodedaccountkey
    container: containername
    rootdirectory: /az/object/name/prefix
    credentials:
      type: client_secret
      clientid: client_id_string
      tenantid: tenant_id_string
      secret: secret_string
    copy_status_poll_max_retry: 10
    copy_status_poll_delay: 100ms
  gcs:
    bucket: bucketname
    keyfile: /path/to/keyfile
    credentials:
      type: service_account
      project_id: project_id_string
      private_key_id: private_key_id_string
      private_key: private_key_string
      client_email: client@example.com
      client_id: client_id_string
      auth_uri: http://example.com/auth_uri
      token_uri: http://example.com/token_uri
      auth_provider_x509_cert_url: http://example.com/provider_cert_url
      client_x509_cert_url: http://example.com/client_cert_url
    rootdirectory: /gcs/object/name/prefix
    chunksize: 5242880
  s3:
    accesskey: awsaccesskey
    secretkey: awssecretkey
    region: us-west-1
    regionendpoint: http://myobjects.local
    forcepathstyle: true
    accelerate: false
    bucket: bucketname
    encrypt: true
    keyid: mykeyid
    secure: true
    v4auth: true
    chunksize: 5242880
    multipartcopychunksize: 33554432
    multipartcopymaxconcurrency: 100
    multipartcopythresholdsize: 33554432
    rootdirectory: /s3/object/name/prefix
    usedualstack: false
    loglevel: debug
  inmemory:  # This driver takes no parameters
  tag:
    concurrencylimit: 8
  delete:
    enabled: false
  redirect:
    disable: false
  cache:
    blobdescriptor: redis
    blobdescriptorsize: 10000
  maintenance:
    uploadpurging:
      enabled: true
      age: 168h
      interval: 24h
      dryrun: false
    readonly:
      enabled: false
auth:
  silly:
    realm: silly-realm
    service: silly-service
  token:
    autoredirect: true
    realm: token-realm
    service: token-service
    issuer: registry-token-issuer
    rootcertbundle: /root/certs/bundle
    jwks: /path/to/jwks
    signingalgorithms:
        - EdDSA
        - HS256
  htpasswd:
    realm: basic-realm
    path: /path/to/htpasswd
middleware:
  registry:
    - name: ARegistryMiddleware
      options:
        foo: bar
  repository:
    - name: ARepositoryMiddleware
      options:
        foo: bar
  storage:
    - name: cloudfront
      options:
        baseurl: https://my.cloudfronted.domain.com/
        privatekey: /path/to/pem
        keypairid: cloudfrontkeypairid
        duration: 3000s
        ipfilteredby: awsregion
        awsregion: us-east-1, use-east-2
        updatefrequency: 12h
        iprangesurl: https://ip-ranges.amazonaws.com/ip-ranges.json
  storage:
    - name: redirect
      options:
        baseurl: https://example.com/
http:
  addr: localhost:5000
  prefix: /my/nested/registry/
  host: https://myregistryaddress.org:5000
  secret: asecretforlocaldevelopment
  relativeurls: false
  draintimeout: 60s
  tls:
    certificate: /path/to/x509/public
    key: /path/to/x509/private
    clientcas:
      - /path/to/ca.pem
      - /path/to/another/ca.pem
    clientauth: require-and-verify-client-cert
    letsencrypt:
      cachefile: /path/to/cache-file
      email: emailused@letsencrypt.com
      hosts: [myregistryaddress.org]
      directoryurl: https://acme-v02.api.letsencrypt.org/directory
  debug:
    addr: localhost:5001
    prometheus:
      enabled: true
      path: /metrics
  headers:
    X-Content-Type-Options: [nosniff]
  http2:
    disabled: false
  h2c:
    enabled: false
notifications:
  events:
    includereferences: true
  endpoints:
    - name: alistener
      disabled: false
      url: https://my.listener.com/event
      headers: <http.Header>
      timeout: 1s
      threshold: 10
      backoff: 1s
      ignoredmediatypes:
        - application/octet-stream
      ignore:
        mediatypes:
           - application/octet-stream
        actions:
           - pull
redis:
  tls:
    certificate: /path/to/cert.crt
    key: /path/to/key.pem
    clientcas:
      - /path/to/ca.pem
  addrs: [localhost:6379]
  password: asecret
  db: 0
  dialtimeout: 10ms
  readtimeout: 10ms
  writetimeout: 10ms
  maxidleconns: 16
  poolsize: 64
  connmaxidletime: 300s
  tls:
    enabled: false
health:
  storagedriver:
    enabled: true
    interval: 10s
    threshold: 3
  file:
    - file: /path/to/checked/file
      interval: 10s
  http:
    - uri: http://server.to.check/must/return/200
      headers:
        Authorization: [Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==]
      statuscode: 200
      timeout: 3s
      interval: 10s
      threshold: 3
  tcp:
    - addr: redis-server.domain.com:6379
      timeout: 3s
      interval: 10s
      threshold: 3
proxy:
  remoteurl: https://registry-1.docker.io
  username: [username]
  password: [password]
  exec:
    command: docker-credential-helper
    lifetime: 1h
  ttl: 168h
validation:
  manifests:
    urls:
      allow:
        - ^https?://([^/]+\.)*example\.com/
      deny:
        - ^https?://www\.example\.com/
    indexes:
      platforms: List
      platformlist:
      - architecture: amd64
        os: linux

In some instances a configuration option is optional but it contains child options marked as required. In these cases, you can omit the parent with all its children. However, if the parent is included, you must also include all the children marked required.

version: 0.1

The version option is required. It specifies the configuration’s version. It is expected to remain a top-level field, to allow for a consistent version check before parsing the remainder of the configuration file.

The log subsection configures the behavior of the logging system. The logging system outputs everything to stderr. You can adjust the granularity and format with this configuration section.

log:
  accesslog:
    disabled: true
  level: debug
  formatter: text
  fields:
    service: registry
    environment: staging

accesslog:
  disabled: true

Within log, accesslog configures the behavior of the access logging system. By default, the access logging system outputs to stdout in Combined Log Format. Access logging can be disabled by setting the boolean flag disabled to true.

hooks:
  - type: mail
    levels:
      - panic
    options:
      smtp:
        addr: smtp.sendhost.com:25
        username: sendername
        password: password
        insecure: true
      from: name@sendhost.com
      to:
        - name@receivehost.com

The hooks subsection configures the logging hooks’ behavior. This subsection includes a sequence handler which you can use for sending mail, for example. Refer to loglevel to configure the level of messages printed.

DEPRECATED: Please use log instead.

loglevel: debug

Permitted values are error, warn, info and debug. The default is info.

storage:
  filesystem:
    rootdirectory: /var/lib/registry
  azure:
    accountname: accountname
    accountkey: base64encodedaccountkey
    container: containername
  gcs:
    bucket: bucketname
    keyfile: /path/to/keyfile
    credentials:
      type: service_account
      project_id: project_id_string
      private_key_id: private_key_id_string
      private_key: private_key_string
      client_email: client@example.com
      client_id: client_id_string
      auth_uri: http://example.com/auth_uri
      token_uri: http://example.com/token_uri
      auth_provider_x509_cert_url: http://example.com/provider_cert_url
      client_x509_cert_url: http://example.com/client_cert_url
    rootdirectory: /gcs/object/name/prefix
  s3:
    accesskey: awsaccesskey
    secretkey: awssecretkey
    region: us-west-1
    regionendpoint: http://myobjects.local
    forcepathstyle: true
    accelerate: false
    bucket: bucketname
    encrypt: true
    keyid: mykeyid
    secure: true
    v4auth: true
    chunksize: 5242880
    multipartcopychunksize: 33554432
    multipartcopymaxconcurrency: 100
    multipartcopythresholdsize: 33554432
    rootdirectory: /s3/object/name/prefix
    loglevel: debug
  inmemory:
  delete:
    enabled: false
  cache:
    blobdescriptor: inmemory
    blobdescriptorsize: 10000
  maintenance:
    uploadpurging:
      enabled: true
      age: 168h
      interval: 24h
      dryrun: false
    readonly:
      enabled: false
  redirect:
    disable: false

The storage option is required and defines which storage backend is in use. You must configure exactly one backend. If you configure more, the registry returns an error. You can choose any of these backend storage drivers:

For testing only, you can use the inmemory storage driver. If you would like to run a registry from volatile memory, use the filesystem driver on a ramdisk.

If you are deploying a registry on Windows, a Windows volume mounted from the host is not recommended. Instead, you can use a S3 or Azure backing data-store. If you do use a Windows volume, the length of the PATH to the mount point must be within the MAX_PATH limits (typically 255 characters), or this error will occur:

mkdir /XXX protocol error and your registry will not function properly.

Currently, upload purging and read-only mode are the only maintenance functions available.

Upload purging is a background process that periodically removes orphaned files from the upload directories of the registry. Upload purging is enabled by default. To configure upload directory purging, the following parameters must be set.

Note: age and interval are strings containing a number with optional fraction and a unit suffix. Some examples: 45m, 2h10m, 168h.

If the readonly section under maintenance has enabled set to true, clients will not be allowed to write to the registry. This mode is useful to temporarily prevent writes to the backend storage so a garbage collection pass can be run. Before running garbage collection, the registry should be restarted with readonly’s enabled set to true. After the garbage collection pass finishes, the registry may be restarted again, this time with readonly removed from the configuration (or set to false).

Use the delete structure to enable the deletion of image blobs and manifests by digest. It defaults to false, but it can be enabled by writing the following on the configuration file:

delete:
  enabled: true

Use the cache structure to enable caching of data accessed in the storage backend. Currently, the only available cache provides fast access to layer metadata, which uses the blobdescriptor field if configured.

You can set blobdescriptor field to redis or inmemory. If set to redis,a Redis pool caches layer metadata. If set to inmemory, an in-memory map caches layer metadata.

NOTE: Formerly, blobdescriptor was known as layerinfo. While these are equivalent, layerinfo has been deprecated.

If blobdescriptor is set to inmemory, the optional blobdescriptorsize parameter sets a limit on the number of descriptors to store in the cache. The default value is 10000. If this parameter is set to 0, the cache is allowed to grow with no size limit.

The tag subsection provides configuration to set concurrency limit for tag lookup. When user calls into the registry to delete the manifest, which in turn then does a lookup for all tags that reference the deleted manifest. To find the tag references, the registry will iterate every tag in the repository and read it’s link file to check if it matches the deleted manifest (i.e. to see if uses the same sha256 digest). So, the more tags in repository, the worse the performance will be (as there will be more S3 API calls occurring for the tag directory lookups and tag file reads if using S3 storage driver).

Therefore, add a single flag concurrencylimit to set concurrency limit to optimize tag lookup performance under the tag section. When a value is not provided or equal to 0, GOMAXPROCS will be used.

tag:
  concurrencylimit: 8

The redirect subsection provides configuration for managing redirects from content backends. For backends that support it, redirecting is enabled by default. In certain deployment scenarios, you may decide to route all data through the Registry, rather than redirecting to the backend. This may be more efficient when using a backend that is not co-located or when a registry instance is aggressively caching.

To disable redirects, add a single flag disable, set to true under the redirect section:

redirect:
  disable: true

auth:
  silly:
    realm: silly-realm
    service: silly-service
  token:
    realm: token-realm
    service: token-service
    issuer: registry-token-issuer
    rootcertbundle: /root/certs/bundle
    jwks: /path/to/jwks
    signingalgorithms:
        - EdDSA
        - HS256
        - ES512
  htpasswd:
    realm: basic-realm
    path: /path/to/htpasswd

The auth option is optional. Possible auth providers include:

• silly
• token
• htpasswd
• [none]

You can configure only one authentication provider.

The silly authentication provider is only appropriate for development. It simply checks for the existence of the Authorization header in the HTTP request. It does not check the header’s value. If the header does not exist, the silly auth responds with a challenge response, echoing back the realm, service, and scope for which access was denied.

The following values are used to configure the response:

Token-based authentication allows you to decouple the authentication system from the registry. It is an established authentication paradigm with a high degree of security.

Available signingalgorithms:

• EdDSA
• HS256
• HS384
• HS512
• RS256
• RS384
• RS512
• ES256
• ES384
• ES512
• PS256
• PS384
• PS512

Default signingalgorithms:

• EdDSA
• HS256
• HS384
• HS512
• RS256
• RS384
• RS512
• ES256
• ES384
• ES512
• PS256
• PS384
• PS512

Additional notes on rootcertbundle:

• The public key of this certificate will be automatically added to the list of known keys.
• The public key will be identified by it’s RFC7638 Thumbprint.

For more information about Token based authentication configuration, see the specification.

The htpasswd authentication backed allows you to configure basic authentication using an Apache htpasswd file. The only supported password format is bcrypt. Entries with other hash types are ignored. The htpasswd file is loaded once, at startup. If the file is invalid, the registry will display an error and will not start.

Warning: If the htpasswd file is missing, the file will be created and provisioned with a default user and automatically generated password. The password will be printed to stdout.

Warning: Only use the htpasswd authentication scheme with TLS configured, since basic authentication sends passwords as part of the HTTP header.

The middleware structure is optional. Use this option to inject middleware at named hook points. Each middleware must implement the same interface as the object it is wrapping. For instance, a registry middleware must implement the distribution.Namespace interface, while a repository middleware must implement distribution.Repository, and a storage middleware must implement driver.StorageDriver.

This is an example configuration of the cloudfront middleware, a storage middleware:

middleware:
  registry:
    - name: ARegistryMiddleware
      options:
        foo: bar
  repository:
    - name: ARepositoryMiddleware
      options:
        foo: bar
  storage:
    - name: cloudfront
      options:
        baseurl: https://my.cloudfronted.domain.com/
        privatekey: /path/to/pem
        keypairid: cloudfrontkeypairid
        duration: 3000s
        ipfilteredby: awsregion
        awsregion: us-east-1, use-east-2
        updatefrequency: 12h
        iprangesurl: https://ip-ranges.amazonaws.com/ip-ranges.json

Each middleware entry has name and options entries. The name must correspond to the name under which the middleware registers itself. The options field is a map that details custom configuration required to initialize the middleware. It is treated as a map[string]interface{}. As such, it supports any interesting structures desired, leaving it up to the middleware initialization function to best determine how to handle the specific interpretation of the options.

Value of ipfilteredby can be:

You can use the redirect storage middleware to specify a custom URL to a location of a proxy for the layer stored by the S3 storage driver.

http:
  addr: localhost:5000
  net: tcp
  prefix: /my/nested/registry/
  host: https://myregistryaddress.org:5000
  secret: asecretforlocaldevelopment
  relativeurls: false
  draintimeout: 60s
  tls:
    certificate: /path/to/x509/public
    key: /path/to/x509/private
    clientcas:
      - /path/to/ca.pem
      - /path/to/another/ca.pem
    clientauth: require-and-verify-client-cert
    minimumtls: tls1.2
    ciphersuites:
      - TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
      - TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
    letsencrypt:
      cachefile: /path/to/cache-file
      email: emailused@letsencrypt.com
      hosts: [myregistryaddress.org]
      directoryurl: https://acme-v02.api.letsencrypt.org/directory
  debug:
    addr: localhost:5001
  headers:
    X-Content-Type-Options: [nosniff]
  http2:
    disabled: false
  h2c:
    enabled: false

The http option details the configuration for the HTTP server that hosts the registry.

The tls structure within http is optional. Use this to configure TLS for the server. If you already have a web server running on the same host as the registry, you may prefer to configure TLS on that web server and proxy connections to the registry server.

Available cipher suites:

• TLS_RSA_WITH_RC4_128_SHA
• TLS_RSA_WITH_3DES_EDE_CBC_SHA
• TLS_RSA_WITH_AES_128_CBC_SHA
• TLS_RSA_WITH_AES_256_CBC_SHA
• TLS_RSA_WITH_AES_128_CBC_SHA256
• TLS_RSA_WITH_AES_128_GCM_SHA256
• TLS_RSA_WITH_AES_256_GCM_SHA384
• TLS_ECDHE_ECDSA_WITH_RC4_128_SHA
• TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA
• TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA
• TLS_ECDHE_RSA_WITH_RC4_128_SHA
• TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA
• TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA
• TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA
• TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256
• TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256
• TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
• TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
• TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
• TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
• TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
• TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
• TLS_AES_128_GCM_SHA256
• TLS_AES_256_GCM_SHA384
• TLS_CHACHA20_POLY1305_SHA256

Default cipher suites:

• TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384
• TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384
• TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256
• TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256
• TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256
• TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
• TLS_AES_128_GCM_SHA256
• TLS_CHACHA20_POLY1305_SHA256
• TLS_AES_256_GCM_SHA384

The letsencrypt structure within tls is optional. Use this to configure TLS certificates provided by Let’s Encrypt.

NOTE: When using Let’s Encrypt, ensure that the outward-facing address is accessible on port 443. The registry defaults to listening on port 5000. If you run the registry as a container, consider adding the flag -p 443:5000 to the docker run command or using a similar setting in a cloud configuration. You should also set the hosts option to the list of hostnames that are valid for this registry to avoid trying to get certificates for random hostnames due to malicious clients connecting with bogus SNI hostnames. Please ensure that you have the ca-certificates package installed in order to verify letsencrypt certificates.

The debug option is optional . Use it to configure a debug server that can be helpful in diagnosing problems. The debug endpoint can be used for monitoring registry metrics and health, as well as profiling. Sensitive information may be available via the debug endpoint. Please be certain that access to the debug endpoint is locked down in a production environment. The debug endpoint should not be exposed publicly to the internet. Instead, keep the debug endpoint private or enforce authentication for it.

The debug section takes a single required addr parameter, which specifies the HOST:PORT on which the debug server should accept connections.

If configured, notification, redis, and proxy statistics are exposed at /debug/vars in JSON format.

prometheus:
  enabled: true
  path: /metrics

The prometheus option defines whether the prometheus metrics are enabled, as well as the path to access the metrics.

The prometheus metrics cover storage, notification and proxy statistics.

The url to access the metrics is HOST:PORT/path, where HOST:PORT is defined in addr under debug.

The headers option is optional . Use it to specify headers that the HTTP server should include in responses. This can be used for security headers such as Strict-Transport-Security.

The headers option should contain an option for each header to include, where the parameter name is the header’s name, and the parameter value a list of the header’s payload values.

Including X-Content-Type-Options: [nosniff] is recommended, so that browsers will not interpret content as HTML if they are directed to load a page from the registry. This header is included in the example configuration file.

The http2 structure within http is optional. Use this to control HTTP/2 over TLS settings for the registry. If tls is not configured this option is ignored. To enable HTTP/2 over non TLS connections use h2c instead.

The h2c structure within http is optional. Use this to control H2C (HTTP/2 Cleartext) settings for the registry. Useful when deploying the registry behind a load balancer (e.g. Google Cloud Run)

notifications:
  events:
    includereferences: true
  endpoints:
    - name: alistener
      disabled: false
      url: https://my.listener.com/event
      headers: <http.Header>
      timeout: 1s
      threshold: 10
      backoff: 1s
      ignoredmediatypes:
        - application/octet-stream
      ignore:
        mediatypes:
           - application/octet-stream
        actions:
           - pull

The notifications option is optional and currently may contain a single option, endpoints.

The endpoints structure contains a list of named services (URLs) that can accept event notifications.

The events structure configures the information provided in event notifications.

Declare parameters for constructing the redis connections. Registry instances may use the Redis instance for several applications. Currently, it caches information about immutable blobs. Most of the redis options control how the registry connects to the redis instance.

You should configure Redis with the allkeys-lru eviction policy, because the registry does not set an expiration value on keys.

Under the hood distribution uses go-redis Go module for Redis connectivity and its UniversalOptions struct.

You can optionally specify TLS configuration on top of the UniversalOptions settings.

Use these settings to configure Redis TLS:

redis:
  tls:
    certificate: /path/to/cert.crt
    key: /path/to/key.pem
    clientcas:
      - /path/to/ca.pem
  addrs: [localhost:6379]
  password: asecret
  db: 0
  dialtimeout: 10ms
  readtimeout: 10ms
  writetimeout: 10ms
  maxidleconns: 16
  poolsize: 64
  connmaxidletime: 300s

health:
  storagedriver:
    enabled: true
    interval: 10s
    threshold: 3
  file:
    - file: /path/to/checked/file
      interval: 10s
  http:
    - uri: http://server.to.check/must/return/200
      headers:
        Authorization: [Basic QWxhZGRpbjpvcGVuIHNlc2FtZQ==]
      statuscode: 200
      timeout: 3s
      interval: 10s
      threshold: 3
  tcp:
    - addr: redis-server.domain.com:6379
      timeout: 3s
      interval: 10s
      threshold: 3

The health option is optional, and contains preferences for a periodic health check on the storage driver’s backend storage, as well as optional periodic checks on local files, HTTP URIs, and/or TCP servers. The results of the health checks are available at the /debug/health endpoint on the debug HTTP server if the debug HTTP server is enabled (see http section).

The storagedriver structure contains options for a health check on the configured storage driver’s backend storage. The health check is only active when enabled is set to true.

The file structure includes a list of paths to be periodically checked for the
existence of a file. If a file exists at the given path, the health check will fail. You can use this mechanism to bring a registry out of rotation by creating a file.

The http structure includes a list of HTTP URIs to periodically check with HEAD requests. If a HEAD request does not complete or returns an unexpected status code, the health check will fail.

The tcp structure includes a list of TCP addresses to periodically check using TCP connection attempts. Addresses must include port numbers. If a connection attempt fails, the health check will fail.

proxy:
  remoteurl: https://registry-1.docker.io
  username: [username]
  password: [password]
  ttl: 168h

The proxy structure allows a registry to be configured as a pull-through cache to an upstream registry such as Docker Hub. See mirror for more information. Pushing to a registry configured as a pull-through cache is unsupported.

To enable pulling private repositories (e.g. batman/robin), specify one of the following authentication methods for the pull-through cache to authenticate with the upstream registry via the v2 Distribution registry authentication scheme.]

The username and password used to authenticate with the upstream registry to access the private repositories.

Run a custom exec-based Docker credential helper to retrieve the credentials to authenticate with the upstream registry.

Note: These private repositories are stored in the proxy cache’s storage. Take appropriate measures to protect access to the proxy cache.

validation:
  disabled: false

Use these settings to configure what validation the registry performs on content.

Validation is performed when content is uploaded to the registry. Changing these settings will not validate content that has already been accepting into the registry.

The disabled flag disables the other options in the validation section. They are enabled by default. This option deprecates the enabled flag.

Use the manifests subsection to configure validation of manifests. If disabled is false, the validation allows nothing.

validation:
  manifests:
    urls:
      allow:
        - ^https?://([^/]+\.)*example\.com/
      deny:
        - ^https?://www\.example\.com/

The allow and deny options are each a list of regular expressions that restrict the URLs in pushed manifests.

If allow is unset, pushing a manifest containing URLs fails.

If allow is set, pushing a manifest succeeds only if all URLs match one of the allow regular expressions and one of the following holds:

1. deny is unset.
2. deny is set but no URLs within the manifest match any of the deny regular expressions.

By default the registry will validate that all platform images exist when an image index is uploaded to the registry. Disabling this validatation is experimental because other tooling that uses the registry may expect the image index to be complete.

validation: manifests: indexes: platforms: [all|none|list] platformlist: - os: linux architecture: amd64

Use these settings to configure what validation the registry performs on image index manifests uploaded to the registry.

Set platformexist to all (the default) to validate all platform images exist. The registry will validate that the images referenced by the index exist in the registry before accepting the image index.

Set platforms to none to disable all validation that images exist when an image index manifest is uploaded. This allows image lists to be uploaded to the registry without their associated images. This setting is experimental because other tooling that uses the registry may expect the image index to be complete.

Set platforms to list to selectively validate the existence of platforms within image index manifests. This setting is experimental because other tooling that uses the registry may expect the image index to be complete.

When platforms is set to list, set platformlist to an array of platforms to validate. If a platform is included in this the array and in the images contained within an index, the registry will validate that the platform specific image exists in the registry before accepting the index. The registry will not validate the existence of platform specific images in the index that do not appear in the platformlist array.

This parameter does not validate that the configured platforms are included in every index. If an image index does not include one of the platform specific images configured in the platformlist array, it may still be accepted by the registry.

Each platform is a map with two keys, os and architecture, as defined in the OCI Image Index specification.

You can use this simple example for local development:

version: 0.1
log:
  level: debug
storage:
    filesystem:
        rootdirectory: /var/lib/registry
http:
    addr: localhost:5000
    secret: asecretforlocaldevelopment
    debug:
        addr: localhost:5001

This example configures the registry instance to run on port 5000, binding to localhost, with the debug server enabled. Registry data is stored in the /var/lib/registry directory. Logging is set to debug mode, which is the most verbose.

See config-example.yml for another simple configuration. Both examples are generally useful for local development.

This example configures Amazon Cloudfront as the storage middleware in a registry. Middleware allows the registry to serve layers via a content delivery network (CDN). This reduces requests to the storage layer.

Cloudfront requires the S3 storage driver.

This is the configuration expressed in YAML:

middleware:
  storage:
  - name: cloudfront
    disabled: false
    options:
      baseurl: http://d111111abcdef8.cloudfront.net
      privatekey: /path/to/asecret.pem
      keypairid: asecret
      duration: 60s

See the configuration reference for Cloudfront for more information about configuration options.

Cloudfront keys exist separately from other AWS keys. See the documentation on AWS credentials for more information.